Offset wrench apparatus

ABSTRACT

A pneumatically driven motor assembly causing rotation of the drive shaft, the drive shaft rotating a drive gear which rotates an idler gear assembly including a pair of simultaneously driven, spaced-apart, idler gears, a wrench gear being driven by the pair of idler gears with the wrench gear having a radial opening therein to be able to cooperate with a polygonal-shaped fastening device, a positioning pawl secured to the drive shaft, a stop being longitudinally movable along the drive shaft upon actuation of the trigger, upon release of the trigger the stop contacts the positioning pawl thereby locating the wrench gear in a particular predetermined positioned.

United States Patent Inventor Daniel P. Juhasz [56] References Cited Garden, UNITED STATES PATENTS gipepci No. 1970 3,535,960 10/1970 Borries 81/57.14 Patented Au 971 3,477,318 11/1969 Batten 81/573 Assignee i' g g lndmria Inc 3,257,877 6/1966 Ulrich et a1. 81/5714 X Los Angeles, Calif. Primary Examiner-James L. Jones, Jr.

Attorney-Robert E. Geauque ABSTRACT: A neumaticall driven motor assembly causing p y rotation of the drive shaft, the drive shaft rotating a drive gear which rotates an idler gear assembly including a pair of simultaneously driven, spaced-apart, idler gears, a wrench gear :{PARATUS being driven by the pair of idler gears with the wrench gear g having a radial opening therein to be able to cooperate with a US. C11 81/5114, polygonal-shaped fastening device, a positioning pawl secured 81 /57.3 to 'the drive shaft, a stop being longitudinally movable along Int. Cl 18251) 17/00, the drive shaft u on actuation of the trig er, u on release of P g P B25b21/00 the trigger the stop contacts the positioning paw1 thereby Field of Search 81/57.l4, locating the wrench gear in a particuiar predetermined posi- 57.3,58.2 tioned.

tz A9 w 52 4% Z? ..s, f s t 46 $0 3 1 6 $l-g x 7 l a 7a ffi geg 4 s Q 2.. L I 32 35 UlFlFSE'll WRENCH APPARATUS BACKGROUND OF THE lNVENTlON In the manufacturing of products it is common to employ tools such as wrenches which are operated pneumatically. in the assembling of many products, there are frequently a great number of fastening devices which are employed. Usually such fastening devices, such as bolts, employ a polygonal shaped head and a cooperating polygonal-shaped nut. Heretofore, to tighten such fastening devices manually has been found to be economically unfeasible. Therefore, a poweroperated portable tool, which can be easily carried by the operator, is usually employed. Normally, such tools are operated through compressed air lines from an air compressor. Although many types of motor assemblies could he employed, it is relatively common to employ the use of a vanetype of motor.

The most common type of powered wrenches is where the wrench element, to effect the tightening of the fastening devices, is of the socket type. Although the socket type of wrench is suitable for most applications, in a great many closed quarters situations a socket type of wrench cannot be employed. To overcome the disadvantages of the socket type of wrench, an open end type of wrench has been employed. The open-end type of wrench usually comprises a gear-driven rotatable member within which there is a radial opening which is to cooperate with a polygonal-shaped fastening device to effect the tightening thereof. The open-end wrench is usually driven by a gear assembly which in turn is caused to rotate from the pneumatic motor assembly. The axis of rotation of the wrench gear is offset from the axis of rotation of the drive shaft and located within a narrow housing which permits access of the wrench gear to confined quarters. As each wrench gear has only one radial opening therein and as the wrench gear housing only has a single opening therein, upon inactivation of the motor unit, it is desired that alignment of such openings occurs automatically. As a result, removal of the fastening device from the wrench gear is permitted and also open-end of the wrench gear with another fastening device is allowed.

Previously, to effect such alignment, it has been common to employ a complex and costly electronic apparatus. in other situations, no automatic alignment apparatus is employed with the alignment being effected manually. Clearly, the manual alignment is time consuming. Therefore, it is more desirable to employ an automatic alignment apparatus. However, the complexity of such electronic alignment apparatus not only increases initial cost and the maintenance cost but the time lost in performing such maintenance is another contributing disadvantage.

lt would be desirable to design an offset open-end wrench apparatus which is pneumatically powered and which employs an automatic alignment structure which is simple in construc tion and which operates efficiently and accurately and is practically maintenance free.

SUMMARY OF THE lNVENTlON The offset wrench of this invention is designed to be primarily portable with the overall configuration being similar to a handgun having a grip, a barrel, and a trigger to effect actuation of the wrench. The trigger causes actuation of a valve which is to permit conductance of an operating fluid (such as pressurized air) to a motor assembly. The motor assembly, located within the barrel, is of any conventional pneumatic motor design. The produced torque from the motor assembly is transmitted through a rotatable shaft to a drive gear. The drive gear causes rotation of a main idler gear offset from the drive gear, which in turn effects simultaneous rotation of first and second idler gears. The first and second idler gears rotate a wrench gear with the wrench gear having a radial opening therein to cooperate with the polygonal fastening device such as the head of a bolt or the attaching nut. The wrench gear, the

first and second idler gears, the main idler gear, and the drive gear are all rotatably mounted within a wrench gear housing. The wrench gear housing has an opening therein to permit access of the fastening device to the wrench gear. To align the radial opening of the wrench gear with the opening within the wrench gear housing, a positioning pawl is located upon the drive shaft. The positioning pawl is to be able to contact a stop which is longitudinally movable in direct relation to the trigger. The stop comprises the free end of a bar which is movably mounted within the barrel. Upon release of the trigger, the drive shaft continues to rotate inertially until the positioning pawl contacts the stop, thereby aligning the radial opening of the wrench gear with the opening within the wrench gear housing.

BRlEF DESCRIPTION OF THE DRAWBNGS FIG. l is a longitudinally, partly insection view of the portable, motondriven, open-end offset wrench assembly of this invention;

FIG. 2 is a front view of the offset wrench gear housing assembly taken along line 2-2 of HG. l; and

FIG. 3 is a sectional view of the positioning pawl and stop assembly taken along line 3-3 of HG. l.

DETAlLED DESCRllPTlON OF THE SHOWN EMBODIMENT Referring particularly to the drawing there is shown in FIG. ll an offset wrench assembly 110, having a grip portion 112, a barrel portion M, a trigger assembly to and a wrench housing lltl attached to the extremity of the barrel portion M. Within the grip i2 is located a conduit 20 which is to conduct pressurized fluid from a source, not shown, to the motor assembly 22 located within the barrel portion M. Trigger assembly 16 includes a trigger 2a which is to be capable of being manually moved against spring 26 thereby manually moving actuator 23. Actuator 2b is supported within cylinder 30 which is fixedly secured to grip 112 with the limits of movement of actuator 28 being defined by pin 32 located within slot 3%. A lowt'riction ball element 1% is located in the end of actuator 28 with ball element 36 operating against cam element Bid. Upon movement of actuator 2% into grip I112, cam element 3% is pivoted causing depression of valve rod M) which thereby causes conductance of pressurized fluid through conduit 20 to motor assembly 22.

Motor assembly 22 effects rotation of a drive shaft d2 which in turn causes rotation of a drive gear M fixedly secured to the free end of shaft 42. It is to be understood that conventional gearing down mechanisms, such as the planetary gear system and appropriate clutching mechanism, may be included within barrel lid, between drive shaft 32 and motor assembly 22. inclusion of such a gearing down mechanism and a clutching mechanism is common to avoid damage to the wrench assembly during use. Drive shaft d2 is supported by bearing as and aid within the barrel M. Bearing do is directly secured to barrel M with hearing being secured to drive shaft housing 50 which is an extension of barrel M. Drive shaft housing 50 is fixedly secured to barrel M by means of bolts $2.

Fixedly secured to drive shaft 42 is a positioning pawl 54}. Pawl 543 is located at a predetermined angular location upon drive shaft 32. One end of pawl 5d is shaped substantially in a point 56. A stop 58 extends through an opening in the drive shaft housing 50 and terminates adjacent drive shaft d2 but not in contact therewith. Stop 58 is movable longitudinally between a first position and a second position. With stop 5% in the first position, pawl M is capable of coming into contact with stop 58. With the stop 5% in the second position, no contaction will result between pawl 5d and stop 58. Stop 58 is fixedly secured to bar 60. Bar 60 is attached to guide 62 which cooperates in a longitudinally movable manner with barrel M. Guide s2 includes ribs which is associated with channelshaped openings within the barrel Ml to provide the sliding movement thereof. Guide at is integrally connected to trigger 24. Thereupon, movement of trigger 24 provides the movement of stop 58 between the first position and the second position.

Drive gear 44 is located within the wrench housing 18 with the drive gear 44 being able to effect rotation of main idler gear 66. Main idler gear 66 is rotatably mounted upon pivot pin 68 within the wrench housing 18. Main idler gear 66 effects simultaneous rotation of a first idler gear 70 and a second idler gear 72. The first idler gear 70 is rotatably mounted upon pin 74 with the second idler gear 72 rotatably mounted upon pin 76. It is to be noted that the plane through the combined axis of rotation of first idler gear 70 and second idler gear 72 is substantially parallel to the drive shaft axis 78. First idler gear 70 and the second idler gear 72 cooperate with a wrench gear 80 to effect rotation thereof. Wrench gear 80 is rotatably mounted within wrench gear housing l8. Wrench gear 80 includes a radial opening 82 which is to be capable of cooperating with a polygonal-shaped fastening device. As the wrench gear 80 is rotated, upon the opening 82 coming into adjacent location to the first drive gear 70 and as a result no driving relationship therebetween occurs, continued rotation of the wrench gear 80 is assured due to second idler gear 72. it is to be understood that a similar relationship occurs upon opening 82 being adjacently located to second idler gear 72.

The operation of the offset wrench of this invention is as follows: The operator of the wrench assembly physically positions a polygonal fastening device such as the head of a bolt or an attaching nut within radial opening 82 of the wrench gear 80. The operator then depresses trigger 24 causing actuation of the motor assembly 22. As a result, drive shaft 42 is rotated and also is drive gear 44. It is to be noted that with trigger 24 depressed, stop 58 is moved to the second position and not capable of coming into contact with positioning pawl 54. Drive gear 44 rotates main idler gear 66 which in turn causes rotation of first and second idler gears 70 and 72, respectively. Thereby, rotation of wrench gear 80 is caused which results in the rotation of the fastening device retained with radial opening 82. It is to be noted that rotation could be in a direction to result in tightening of the fastening device or in a direction to result in loosening the fastening device. However, normally the apparatus 10 of this invention will be employed to effect tightening of the locking device. Upon adequate tightening of the locking device having been achieved, the operator releases trigger 24 which is then biased by spring 26 until stop 58 reaches the first position. Actuator 28 moves forwardly so that cam 38 rotates counterclockwise. As a result, valve rod 40 moves to block the flow of fluid to motor assembly 22, thereby not transmitting torque to drive shaft 42. It is to be noted that the length of spring 26 is selected so that pin 40 is slightly compressed with the trigger 24 released. As a result, fluid bleeds" into the motor assembly 22 causing drive shaft 42 to continue to rotate an additional revolution. In order for the stop 58 to correctly effect the desired alignment of openings 82 and 84, wrench gear 80 and drive gear 44 each have the same number of teeth, except for opening 82. Without this equal teeth arrangement only the main drive shaft 42 would be fixed. As the stop 58 is located in the first position, the positioning pawl 54 is able to come into contact with stop 58. When such occurs, complete stoppage of the drive shaft 42 results. The location of the positioning pawl 54 upon the drive shaft 42 is such that when pawl 54 does come into contactual relationship with stop 58, the radial opening 82 of the wrench gear 80 is in alignment with opening 84 of the wrench gear housing 18. Such alignment permits removal of the polygonal fastening device retained within opening 82. It is to be noted that if stop 58, when moving from the second position to the first position, comes into contact with the pointed end 56 of pawl 54, because of the pointed end 56, pawl 54 will slide past stop 58 and continue for an additional revolution until positive contact between pawl 54 and stop 58 is accomplished.

I claim:

1. An apparatus comprising: a pneumatically dnven portable tool including a grip and a barrel, a driving motor assembly located within said barrel, said grip including a valve to regulate the fiow of driving fluid to said driving motor assembly, said valve being actuatable by a trigger, said trigger being movable between a first position and a second position;

a drive shaft being rotatable by said driving motor assembly, a drive gear being connected to said drive shaft, said drive gear being located within a gear housing;

an idler gear assembly including at least a first and second idler gear, said idler gear assembly being located within said gear housing, said first and second idler gears being rotatable by said drive gear;

a wrench gear being simultaneously rotatably driven by said first and second idler gears, said wrench gear being located within said gear housing, said wrench gear having a radial opening therein to cooperate with a polygonalshaped fastening device, an aperture within said gear housing, said radial opening being alignable with said aperture to permit entry and removal of the fastening device; and

a positioning pawl secured to said drive shaft, a stop movable between a first and second position, said stop being able to contact said positioning pawl with said stop in said first position, with said stop in contact with said positioning pawl said radial opening of said wrench gear in alignment with said aperture of said gear housing.

2. An apparatus as defined in claim 1 wherein:

said stop being movable between said first and second positions by actuation of said trigger.

3. An apparatus as defined in claim 2 wherein:

a bar connecting said stop to said trigger, said bar being movably retained within said barrel.

4. An apparatus as defined in claim 3 wherein:

said positioning pawl is substantially pointed at one end, whereby upon movement of said stop from said second position to said first position and direct contact results between said pointed end and said stop said positioning pawl will continue to rotate another revolution.

5. An apparatus comprising:

a rotatable drive shaft, said drive shaft being secured to a drive gear, said drive gear being connected to an idler gear assembly, said idler gear assembly effecting rotation of a wrench gear, said wrench gear having a radial opening therein to cooperate with a polygonal-shaped fastening device;

a wrench gear housing containing said wrench gear, an aperture within said wrench gear housing, said radial opening being alignable with said aperture to permit entry and removal of the fastening device;

means secured to said drive shaft for positioning said radial opening in alignment with said aperture.

6. An apparatus as defined in claim 5 wherein:

said means includes a positioning pawl, said pawl secured to said drive shaft, said means further includes a stop to be contactable with said pawl, said stop being movable between a first position in contact with said pawl to a second position disassociated with said pawl.

7. An apparatus as defined in claim 6 wherein:

said positioning pawl is substantially pointed at one end, whereby upon movement of said stop from said second position to said first position and direct contact results between said pointed end and said stop said positioning pawl will continue to rotate another revolution. 

1. An apparatus comprising: a pneumatically driven portable tool including a grip and a barrel, a driving motor assembly located within said barrel, said grip including a valve to regulate the flow of driving fluid to said driving motor assembly, said valve being actuatable by a trigger, said trigger being movable between a first position and a second position; a drive shaft being rotatable by said driving motor assembly, a drive gear being connected to said drive shaft, said drive gear being located within a gear housing; an idler gear assembly including at least a first and second idler gear, said idler gear assembly being located within said gear housing, said first and second idler gears being rotatable by said drive gear; a wrench gear being simultaneously rotatably driven by said first and second idler gears, said wrench gear being located within said gear housing, said wrench gear having a radial opening therein to cooperate with a polygonal-shaped fastening device, an aperture within said gear housing, said radial opening being alignable with said aperture to permit entry and removal of the fastening device; and a positioning pawl secured to said drive shaft, a stop movable between a first and second position, said stop being able to contact said positioning pawl with said stop in said first position, with said stop in contact with said positioning pawl said radial opening of said wrench gear in alignment with said aperture of said gear housing.
 2. An apparatus as defined in claim 1 wherein: said stop being movable between said first and second positions by actuation of said trigger.
 3. An apparatus as defined in claim 2 wherein: a bar connecting said stop to said trigger, said bar being movably retained within said barrel.
 4. An apparatus as defined in claim 3 wherein: said positioning pawl is substantially pointed at one end, whereby upon movement of said stop from said second position to said first position and direct contact results between said pointed end and said stop said positioning pawl will continue to rotate another revolution.
 5. An apparatus comprising: a rotatable drive shaft, said drive shaft being secured to a drive gear, said drive gear being connected to an idler gear assembly, said idler gear assembly effecting rotation of a wrench gear, said wrench gear having a radial opening therein to cooperate with a polygonal-shaped fastening device; a wrench gear housing containing said wrench gear, an aperture within said wrench gear housing, said radial opening being alignable with said aperture To permit entry and removal of the fastening device; means secured to said drive shaft for positioning said radial opening in alignment with said aperture.
 6. An apparatus as defined in claim 5 wherein: said means includes a positioning pawl, said pawl secured to said drive shaft, said means further includes a stop to be contactable with said pawl, said stop being movable between a first position in contact with said pawl to a second position disassociated with said pawl.
 7. An apparatus as defined in claim 6 wherein: said positioning pawl is substantially pointed at one end, whereby upon movement of said stop from said second position to said first position and direct contact results between said pointed end and said stop said positioning pawl will continue to rotate another revolution. 